Comparison of the Marginal Fit of Cobalt-Chromium Metal-Ceramic Crowns Fabricated by CAD/CAM Techniques and Conventional Methods at Three Production Stages

Purpose: The aim of this study was to compare the marginal fit of cobalt-chromium crowns fabricated using conventional casts and computer-aided design/computer-assisted manufacturing (CAD/CAM) techniques at three stages of production: metal coping, after porcelain firing, and after cementation. Materials and methods: A total of 80 metal-ceramic crowns were fabricated using four different techniques: lost wax casting, milling, laser sintering, and milling of a presintered metal block. Marginal fit was measured at each manufacturing stage. Results: The porcelain firing stage improved marginal fit. CAD/CAM techniques resulted in better marginal fit than did conventional casting techniques at all manufacturing stages. Conclusion: CAD/CAM techniques improve marginal fit.